Anchorage nail



March 3, 1970 E.1'HURNER 3,498,172

- vANCHORAGE NAIL Filed Jan'. 16; 1969 2 sheets-sheet 1 ATTORNEYS March 3, 1970 E. THURNER 3,498,172

ANCHORAGE NAIL Filed Jan. 16, 1969 Y 2 Sheets-Sheet 2 J /V VEN 702 rl/W42 TVI/RIVER United States Patent O 3,498,172 ANCHORAGE NAIL Elmar Thurner, Feldkirch-Gisingen, Austria, assignor to HILTI Aktiengesellschaft, Schaan, Liechtenstein Continuation-in-part of application Ser. No. 704,753, Feb. 12, 1968. This application Jan. 16, 1969, Ser. No. 791,554

Claims priority, application Germany, Mar. 7, 1967,

Int. Cl. F16b 15/02 U.S. Cl. 85-28 5 Claims ABSTRACT OF THE DISCLOSURE A nail of a type which is adapted to be driven in a hard receiving material such as concrete includes a large head diameter compared to its shaft diameter. The nail shaft is widened in a convex manner toward the head over a length adjacent the head corresponding substantially to the shaft diameter. The widening curve is preferably made such that the rst and second thirds of the curve in a direction proceeding toward the head are relatively flat but become rapidly steep in the last third-portion which terminates in the outside diameter of the rim of the head. A flat rim of a height which is less than half the height of the total head portion is stamped around the head. The rim diameter is substantially double or triple the shaft diameter. The head is formed with a raised central portion which is either curved or convex or includes a raised central at portion.

CROSS REFERENCE TO RELATED APPLICATION This invention is a continuation-in-part application of my copending patent application Ser. No. 704,753, led on Feb. 12, 1968.

SUMMARY OF THE INVENTION This invention relates, in general, to the construction of anchoring devices and, in particular, to a new and useful nail which is adapted to be driven into a hard receiving material such as a concrete by a driving piston which may be handor power-operated and which includes a large head diameter compared to its shaft diameter.

In bolt setting devices where the driving energy for driving a nail into a hard receiving material is transmitted with a hammer piston to the nail, a guide disk is usually attached to the shaft of the nail in order to form a guide for the front portion thereof. Instead of using a second guide disk, the nail head is frequently designed so that it provides a rear orientation or guidance of the nail in the barrel of the driving device. If such a nail having a head diameter which is rather large compared to its shaft diameter penetrates obliquely into the receiving material, the nail head is pressed flat to the receiving material by the energy of the hammer piston. A lever effect is produced in this process and there is a tendency for the nail head to become deformed or torn oft when the known types of nails are employed. In the event that the head is torn off, it may injure the operator of the device or the people standing around. Besides, the destroyed nail is no longer useful as a supporting fastening element.

The above disadvantages are avoided by providing a nail head with a relatively large head portion and which includes a shaft portion which is widened in a convex manner adjacent the head. The convex widening curve is formed over a length of the shaft which corresponds substantially to the shaft diameter but which may be in a range of from not less than half the diameter to not more than 11/2 times the diameter. The widening curve formed on the shaft portion adjacent the head is relatively flat in 3,498,172 Patented Mar. 3, 1970 ICC the first and second third-portions thereof but becomes much deeper in the last third-portion and terminates in the outside diameter of the head edge or rim. With such a construction, the bending strength is increased considerably in the area of the shaft directly adjacent the head so that a tendency toward detachment of the nail head during driving-in is avoided. This is true even though the nail may be driven-in obliquely.

In the preferred embodiment of the construction, the

nail includes a head which has a flat rim extending around the head and which absorbs the residual energy of the hammer piston when the head strikes the target or receiving material. If the head penetrates obliquely into the receiving material, the head rim is stressed by a lever action so that the rirn may be deformed or partly sheared off. This permits the nail to perform its function despite the deformed head rim.

The nail head is advantageously formed With the top portion of the head shaped convexly or with a bulbous configuration having a central apex. Another embodiment includes a raised substantially cylindrically-shaped top portion of the nail head. This raised cylindrical top portion is advantageously made to a diameter corresponding to the shaft portion.

Accordingly, it is an object of the invention to provide an improved nail construction for use with a hand or explosive-powder operated bolt setting device which includes a widened head portion and a shaft with a portion adjacent the head which widens in a convex manner over a curve which is relatively flat at the shaft portion and increases rapidly toward the head and terminates at the rim of the head.

A further object of the invention is to provide a nail with a widened head and a widened shaft portion adjacent the head and which includes a flat rim which is stamped around the head and wherein the rim diameter is preferably double or triple the shaft diameter.

A further object of the invention is to provide a nail construction which is simple in design, rugged in construction and economical to manufacture.

The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this specification. Fol a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descripltive matter in which there is illustrated and described a preferred embodiment of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS GENERAL DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, in particular, the invention embodied therein in FIG. 1 comprises a nail generally designated 1 having a cylindrical shaft 2 with a convexly curved widened portion 3 and a relatively wide head 4 with a at rim 5 extending around it.

In accordance with the invention, the convex widened portion 3 is of a length corresponding substantially to the shaft diameter but which may be in a range which varies from half the shaft diameter to 11/2 times the shaft 3 diameter. The widening curve of the widened portion 3 is relatively flat in the first and second third-portions and becomes rapidly steep in the last third-portion adjacent the head. The steep portion of the curve terminates in the outside diameter of the head rim.

The nail 1 is used with a bolt setting device generally designated for driving the nail into a hard receiving material such as a concrete 12. The nail 1 is positioned within a barrel 6 of the setting device 10 after a washer or guide disk 8 is engaged around its lower end. The rim 5 which is substantially equal to the interior diameter of the barrel `6 provides an upper guide for the nail. As indicated in FIG. 3, the hammer piston 7 of the driving device moves downwardly to drive the nail into the concrete 12. In the illustrated embodiment, the nail has penetrated obliquely into the receiving material 12. The head rim 5 bears unilaterally on the receiving material and the guide disk 8 and each is deformed. However, even in this extreme condition there is no breaking off of the head and the nail 1 still functions as an adequate securing device.

In the embodiment of FIG. 4, a nail 1 has a cylindrical shaft 2', a concavely widening portion 3', a head generally designated 4', and a circumferential fiat border 5' with a cylindrical edge parallel to the longitudinal axis of the nail. On the end face of the nail head is provided a shoulder or cylindrical raised portion 9, whose diameter corresponds substantially to the shaft diameter. This shoulder 9 has in the represented case an end face 11 which extends in a normal plane of the nail axis.

The broken line 4a indicates the form of a club which is circumscribed by the nail head and around which extends the preferably stamped-on head border 5 whose outside diameter is approximately 2 to 3 times the shaft diameter and which corresponds to the inside diameter of the gun or setting tool (not shown) with which it may be used.

It is important that the capacity of the nail for absorbing shearing and bending forces is lower in the transition range of the head border 5 into the club form 4a (point A) than in the transition range of the shaft to the head (point B). The forces that can be absorbed at point A will naturally be the greater the stronger point B is made.

The combination of a club-shaped head form of the configuration of the dotted outline 4a with the circular fiat edge having a predetermined breaking point, has the result that a maximum absorption power is obtained for the occurring shearing and bending forces in the transition range from the head to the shaft, and when the predetermined stresses are exceeded, the circular flat head edge will be partly sheared off. The excess forces remaining after the deformation of the head edge are so reduced that they no longer can do any harm to the transition zone of the shaft and head, and, in addition, this transition zone is reinforced by the design according to the invention.

Due to the partial shearing or deformation of the head edge, its pull-over force, that is, its function as a holding means, for example, in fastening wooden laths on concrete, is not impaired. This means that the steel rings used for guides can be replaced with the nail according to the invention, if desired, by destructible plastic rings.

What is claimed is:

1. A nail for use with an explosive power operated bolt setting device and which is adapted to be driven into a hard receiving material, comprising a shaft portion terminating in a penetrating point, a head portion having a greater diameter than said shaft portion adjacent one end of said nail, said head portion having an outer raised central portion with its highest part disposed centrally, said head portion also including a flat shallow depth rim portion between said central portion and said shaft portion, said rim portion being of a height less than half the total height of said head portion, said shaft portion including a concave widened portion adjacent said rim portion of an axial length corresponding substantially to the shaft diameter, said widened portion having an exterior con cave surface defining a widened curve which is substantially fiat in the first and second third-portions of the concave widened portion but which becomes rapidly steep in the last third-portion of the concave widened portion and terminates in the outside diameter of said rim portion.

2. A nail, according to claim 1, wherein said central portion of said head is of a convex configuration and including a marginal outer portion above said rim portion which is substantially flat.

3. A nail for use with a hand or explosive power operated bolt setting device and which is adapted to be driven into ahard receiving material, comprising a shaft portion, a head portion larger than said shaft portion adjacent one end of said nail having an outer rim with a cylindrical edge parallel to the longitudinal axis of said nail, said shaft portion including a concave widened portion adjacent said rim of an axial length corresponding substantially to the shaft diameter, said widened portion having an exterior concave surface defining a widening curve which is substantially flat in the first and second thirdportions of the concave widening portion but becomes rapidly steep in the last third-portion of the concave widened portion and terminates in the outside diameter of said rim7 said head having a raised central portion above said head centrally located in respect to said rim, said raised central portion comprising a cylinder having a flat end face.

4. A nail with a large head diameter relative to the shaft diameter for driving into hard receiving material by means of a hand or explosive operated bolt setting tool, said nail having a widened head, a nail shaft which is concavely widened toward said head over a length corresponding substantially to the shaft diameter, and that the widening curve rises fiat in the first third-portion and the second third-portion while it rises steeper in the last thirdportion and terminates at said head, said headhaving a fiat cylindrical rim adjacent its border with said shaft, and a substantially cylindrical shoulder defining the upper extremity of said head and being centrally located with respect to said cylindrical rim, said cylindrical shoulder having a diameter corresponding substantially to the shaft diameter whereby said cylindrical shoulder is axially aligned with the surface of said shaft.

5. A nail, according to claim 4, characterized in that the end face of said shoulder extends in the plane of the nail axis.

References Cited UNITED STATES PATENTS 1,897,335 2/1933 Riedel et al. 85-28 1,944,150 l/l934 Brugge -28 2,140,749 12/ 1938 Kaplan 85-28 2,353,315 7/1944 Maze 85-28 RAMON S. BRITTS, Primary Examiner 

